For existing LED televisions, soft start times of starting moments in different starting modes are the same. When the starting mode is a three-dimension starting mode, a maximum current flowing through the LED is much more than the maximum current flowing through the LED in a two-dimension starting mode. If the soft start times of the starting moments in different starting modes are the same, then it will cause that when the starting mode is the three-dimension starting mode, at the starting moment, the current flowing through the inductor is excessive thus it exceeds the saturation current of the inductor or it exceeds the rated current specification of the field-effect tube.